Javascript error in tableheader.js: $("td" + location.hash).offset() is undefined

Hi,

The following piece of code in tableheader.js causes javascript error $("td" + location.hash).offset() is undefined when a hash is present in the URL that has no relation with table cells.

      if (prevAnchor != location.hash) {
        if (location.hash != '') {
          var scrollLocation = $('td' + location.hash).offset().top - $(e).height();
          $('body, html').scrollTop(scrollLocation);
        }
        prevAnchor = location.hash;
      }

The error happens when the selector 'td' + location.hash does not match any element. In that case, offset().top is undefined.

I think it could be fixed by adding a condition like this:

      if (prevAnchor != location.hash) {
        if (location.hash != '' && $('td' + location.hash).size()) {
          var scrollLocation = $('td' + location.hash).offset().top - $(e).height();
          $('body, html').scrollTop(scrollLocation);
        }
        prevAnchor = location.hash;
      }

I'm making the issue critical because this issue causes javascript errors when a hash is present in the URL that does not match a TD identifier. This javascript error breaks all the javascript present in the site, including ads, analytics, etc.

Please, consider backporting this fix to D6 too.